The present invention generally relates to vehicle controls and, more particularly, to methods and apparatus for adjusting a throttle of a vehicle engine.
Operation of a vehicle generally includes operator adjustment of a throttle to select the operating level of the vehicle engine. For example, operation of an automobile generally includes adjusting the fuel injectors, engine spark and amount of airflow through an intake manifold to an intake port of an internal combustion engine in response to operator adjustment of the throttle. The operator adjustment of the throttle is typically accomplished with an input mechanism, such as a foot pedal, joystick, hand pedal, lever or track ball, which is coupled to an input sensor. The input sensor provides an input signal to a processor that generates the control signals for the hardware of the vehicle engine to provide the operating level indicated by the input mechanism.
The ability of the operator to accurately adjust the input mechanism for a maximum operating level of the vehicle engine can be limited by a number of factors. For example, the physical characteristics of an operator (e.g., height) can limit the ability of the operator to position the input mechanism at a location that provides the maximum operating level of the vehicle engine. In addition, variations in the placement of the input mechanism within a vehicle compartment or variations in obstructions to the motion of the input mechanism (e.g., floor mat thickness) can limit the ability of an operator to obtain the maximum operating level. Therefore, these and other factors that limit the ability of the operator to adjust the input mechanism for a maximum operating level of the vehicle engine can result in undesirable attributes of the throttle, such as a dead pedal at maximum pedal travel.
In view of the foregoing, it should be appreciated that it would be desirable to provide methods and apparatus for adjusting a throttle of a vehicle engine to address these and other variations that limit the ability of an operator to accurately obtain the maximum operating level of the vehicle engine. Furthermore, additional desirable features will become apparent to one skilled in the art from the foregoing background of the invention and following detailed description of a preferred exemplary embodiment and appended claims.
In accordance with the teachings of the present invention, methods and apparatus are provided for adjusting a throttle of a vehicle engine to obtain the maximum operating level of the vehicle engine. The apparatus comprises an input sensor configured to provide an input signal having a value that corresponds to an operating level of the vehicle engine requested by an operator and a memory configured to store a maximum input value for the input sensor. The maximum input value provides the value of the input signal that corresponds to a maximum operating level of the vehicle engine. The apparatus is further configured to receive the input signal and access the memory to retrieve the maximum input value and further configured to update the maximum input value with the value of the input signal if the value of the input signal is greater than the maximum input value. The processor is also configured to generate a throttle control signal that controls the throttle of the vehicle engine using the maximum input value and the input signal.